LTE (Long Term Evolution) refers to evolution of 3G (3rd Generation). It improves and enhances air access technology of 3G and adopts OFDM (Orthogonal Frequency Division Multiplexing) and MIMO (Multiple Input Multiple Output) as the standard for evolution of the LTE wireless network. Therein, power control method of PUCCH (Physical Uplink Control Channel) is specified in the LTE system, which is to calculate PUCCH transmission power by UE (user equipment) side according to configuration and scheduling condition of a base station.
Uplink multi-antenna transmission mode is introduced in LTE-A (LTE-Advanced) system, and transmit diversity technology could be adopted for the PUCCH to improve performance; SORTD mode could be adopted as the specific transmit diversity mechanism, viz. a base station distributes independent PUCCH channel resource to each uplink antenna port of the UE. The UE could send PUCCH by using multiple antenna ports simultaneously and making use of different PUCCH resources respectively.
In the procedure of realizing the objects of the present invention, at least the following problems existing in the current technologies were found:
SORTD is supported by all kinds of PUCCH formats, but it is configured independently for each format to open SORTD or not, viz. it is possible for the UE to send PUCCH format 1a by SORTD while send PUCCH format 2 by single antenna port mode; since the detection performances acquired at a base station side for PUCCH transmission modes of single antenna port and transmit diversity could be distinguished, difference between transmission power of UE and expected power of base station will be caused during application of the current PUCCH power control mode. For example, if SORTD improves detection performance of PUCCH for 3 dB, and the UE still sets power for corresponding PUCCH channel of each antenna port according to the current power control formula and relevant parameter configuration, total output power of the UE will exceed the actual needed transmission power of 3 dB, so that power of the UE is consumed, interference between users and cells is increased, and system performance is wasted.